Method of coking hydrocarbons



Patented li/lay 2 1933 artnr ALEXANDER S. KNOWLEES AND CHARLES W.ANDREWS, 0F CHICAGO, ILLNOS, AS-

SIGNRS TO TAR do PETROLEUM PROCESS COMPANY, 0F CHICAGO, ILLINOIS, A.`

METHGD 0F COKNC-r HYDROCARBGNS Application filed 'March 5,

lhis invention relates to anew and improved method for the treatment ofhydrocarbons, and more particularly to a method of treatment of suchmaterial whereby the volatile constituents are driven oit and the solidresidue is coked. llt relates to the treatment ot any hydrocarbonmaterial, whether normally in liquid form or capable of liquefaction byheat. While it is particularly applicable to the treatment ofhydrocarbon such as the heavy residueof cracking stills in the petroleumindustry, it is also applicable to the treatment of any otherhydrocarbon or similar materials.

`This invention is in the nature of an improvement or modification ofour invention disclosed in our copending application Serial Nd 277,618,led May 1t, 1928,

'llhe process may be described briefly as the treatment ot hydrocarbonin liquid form, which. comprises depositing suchV hydrocarbon in aclosed chamber on a highly heated door, the hydrocarbon being heatedthrough this door and gradually building up a layer ot coke upon theiloor. rlhe rate ot deposit of the material and the rate ot input to thedoor are so related that a layer ot substantially liquid material ismaintained upon the layer ot coke throughout the continuation o' theprocess. At intervals the deposit ot material in liquid form may bestopped while the input ot heat may continue until the entire liquidremaining in the chamber has been reduced tocoke, or the process may beinterrupted without completely coking the liquid layer The layer ofsolid material is then removed from the chamber and after the chamber isclosed the process may continue as before.

llt is an object of the present invention to provide a new and improvedmethod for the treatment of hydrocarbon material in liquid form.

llt is a further object to provide a process of this character in whichthe material is so treated as to crack and break down the material andto volatilize the lighter constituents and to reduce the residue to amerchantable coke.,

llt .is-also an object to provide a method ot 1929. Serial No. 344,131.

this character which may be carried on an It is a further object toprovide a new and improved method for the removal of the solid residueor coke produced by our method.

llt is an additional object to provide a method which may be carried onsubstantially continuously.

Other andturther objects will appear as the description proceeds.

We have shown the one preferred form oit apparat-us for carrying out ourinvention in the accompanying drawing in which- Figure 1 is alongitudinally vertical section through the apparatus;

hdigure 2' is a transverse vertical section; an

Figure 3 is a. fragmentary vertical section showing a modified form ofconstruction.

Referring first to the :torni of construction shown in Figures 1 andQ,the enclosed cham ber 11 is shown provided with the floor 12.,

' rllhis lioor is formed of highly refractory material or heat resistantmetal, and is heated` from below by means of combustion which takesplace in the lues 13 located below the tloor. 'llhese lues vmay beheated b, means ot uel introduced through the fue supply pipe 14,located at the opposite end of the lines. 'llhe iues 13 are connected tothe regenerators 15, which are connected in turn to the passages 16which serve alternately to introduce the airofor combustion, and tocarry od the products of combustion. llt will be understood that thecombustion in this iue is shown as carried on alternately air passes upthrough opening 17 to mingle with the fuel to cause the initialcombustion, and additional air will pass up through open-= ings 18 and19 to cause additional combustion. By this means combustion may becarried on for the major portion of the length of the line, and thefloor, therefore, heats substantially uniformly throughout its length.lnstead of reversing the combus-= tion with regeneration, other methodsot heating the floor such as the use of recuperators, may be utilized.

-rom opposite ends. On the incoming end r The upper portion of thechamber 11 is closed by the top which may be made of metal andpreferably may be covered with any material adaptedto minimize the lossthrough radiation. rlFhe ends of the cham'- bers 11 are closed by doors21 which may be removed for the purpose of discharging the coke from thechamber. A second chamber is located above the coking chamber 11 andextends substantially from the middle of the roof 20. This chamber 22 isprovided with a cylindrical basket 23 carried on trunnions 24 and 25.The. trunnion 25 is provided with a power supply pulley 26, to whichpower may be brought from any suitable source. By means of power appliedto pulley 26, the basket 23 may be rotated as desired. rlhe inletchamber 27 is located immediately above lthe basket 23, and contains thetwo downwardly directed inlet nozzles 28. rlfhese nozzles are connectedto the supply pipe 29, the connection being controlled by valve 30. ITheoftake passage 31 leads from the upper portion of the inlet chamber 27.

The bottom of the upper chamber 22 is preferably closed by a butteriyvalve 32 provided for that purpose, as it may be desirable to close offthis chamber when the ends of the coking chamber are open for theremoval of the coke.

Inside the chamber 11 are provided the Z- bars 35 which extend thelength of the chamber and have the inwardly extending flanges 36 whichserve as guides and supports for the pusher used to push the coke fromthe floor 12. The head of the pusher has been shown at the right ofFigure 1 and comprises the lower portion 37 which extends the full widthof the floor, the upper anges 38 to rest on the guide flanges 36 and thepush rod or shaft 39. rl`hrust may be applied to shaft 39 in any desiredmanner and by any desired form of apparatus, such for example as thecoke pushing machine used for rectangular beehive coke ovens.

The form of construction shown in Figure 3 differs from that of Figures1 and 2, in that the upper chamber 33 is provided with a plurality ofdownwardly sloping baffles 34 to receive the material from the inletpipes or nozzles 40 and to expose the material to Contact with theascending gases. These baffles therefore perform the same function asthat performed by the rotating basket, in the first form ofconstruction.

In the operation of the apparatus shown, to carry out our improvedmethods the floor 12 is first raised to a coking temperature by means ofcombustion 'in the flues 13. The

material to be treated is introduced through Lacasse.

the oven directly from such prioi` process while still hot from previousdistillation or cracking action.

rllhe material falls from nozzles 28 upon the basket 23 which basket ispartially filled with a mass of loose material such as coke. @thermaterials than coke may be used as the purpose of this loose material isto provide extended surfaces to receive the liquid being treated inorder to give a more extended contact between the material being treatedand the ases rising from the coking chamber. rlhe asket 23 is rotated tomore uniformly distribute the material being treated throughout theloose material in the basket, and to prevent clogging of the coke or thebuilding up of the material thereon. rihis rotation, however, may bequite slow, as for example approximately one rotation per minute, or itmay be even slower if desired. "While some of the solid residue from theliquid being treated will be deposited upon the material in the basket,due to the rotation of the basket there is a constant abrasion of theloose material. rlhe speed of rotation may be so maintained as tosubstantially knock o' or abrade the material as fast as it is depositedon the loose material in the basket. ln this way the loose material inthe basket may be maintained at substantially a consta-nt size and atsubstantially the same amount.

From the basket 23 the material drops to the highly heated floor 12. Onthe floor the liquid spreads out and the floor is covered with a layerthereof. This layer of liquid is highly heated through the heattransmitted upwardly through the floor, and the lower portion of thelayer is coked. The process continues with material being deposited inthe upper chamber and dripping from the basket to the door. The rate ofdeposit of material and of input of heat to the floor are so related asnot to coke all of the material on the ioor and there is maintained ontop of the coke layer a layer of liquid. Between the hard coke on thebottom and the comparatively liquid top will be an intermediate layervarying in solidity and density. From the liquid layer the vapor andgases given olf pass upwardly through the upper chamber 22, through theinlet chamber 27 and out through the passage 31. During their passagethese gases are brought in contact with the liquid dropping from thebasket 23, as well as with the thin film of liquid covering the loosematerial in the basket or the baffle plates, if that form ofconstruction is used. rlhe temperatures of these gaseousproducts will bemaintained substantially constant throughout the operation, since thistemperature is that at which the gases are driven off or volatilized.The thickness of the layer of liquid in the chamber is controlled tomaintain this temperature substantially constant.

lll)

Leoaeee There is, due to the layer of coke and of liquid on the floor,very little heat radiating from the floor up to the basket 23, but theheat at the basket is that carried by the ascending gases. Due to thisfact the basket 23 may be located well above the floor and in a separatechamber as shown. There is little loss of temperature of the gases inthe short distance between the Hoor and the basket in the upper chamber,all of this distance being within the enclosing chambers.

Tt will be understood that the layer of coke building up on the flooracts in the nature of an insulator and after it has reached apredetermined depth it is not economical to continue to build up uponit, since the heat of further coking must be transmitted through thiscoke layer. Therefore, after the layer has reached a predetermined depththe supply of additional material to be heated is stopped by closing thesupply valve 30. The liquid material in the basket may then be permittedto largely drip to the iioor during which the heating of the floor maybe continued. Tf desired, the heating may be continued until the liquidlayer is fully or partially coked or the material on thepiloor may beremoved without additional delay. Before the doors 21 are opened for thepushing out of the coke, the valve 32 is closed to separate the upperchamber and basket from the coking chamber. This is desirable to preventany ash of combustion passing into the upper chamber when air isadmitted to the highly heated coking chamber bv the opening of thedoors.

After the coke is removed, the doors 21 are'closed, the valve 32 is thenopened and the supply of material to be treated again started. Thesupply of heat to the floor 12 may be interrupted vwhile the doors 21are opened for the removal of coke. Since this removal may be carried onby means of apparatus for that purpose in a very few minutes, there isvery little loss of time or of heat during the removal. The doors may bequickly brought up again to the coking temperature.

When the deposit of material is started again after each removal ofcoke, there is no solid layer of cokeon the oven floor to support theliquid layer as there is as the deposit and coking progress. There isnormally, however, a layer of coke dust or breeze left on the Hoor afterthe coke is pushed out. This results from the breaking up of the coke asit is pushed out and the abrasion of the pieces against each other. Thislayer of coke breeze prevents the next liquid deposited from` cominginto direct contact with the heated floor and therefore prevents toorapid coking of this liquid. The coke breeze willv become a part of thenext layer of coke as it is formed. v

Since in this process we mamtain a layer of liquid materialupon thelayer of coke, it is not necessary to apply the liquid at a number ofpoints throughout the floor area. We have found in actual operation thateven if the liquid is supplied only through a small area such as that ofthe chamber 22, it will, upon reaching the door, spread out to the edgesof the floor. The coke layer built up will be found to besubstantiallyequal in thickness throughout the lioor area. Tt is highlydesirable to be able Ito deposit the liquid in but few points sincematerials of this character tend to clog nozzles or other means fordepositing small amounts of material. By deposit in a localized area thenozzle flow may be made of suicient quantity so as to substantiallyprevent clogging, and also the number of nozzles used may be so smallthat it is a simple matter `t0 take care of them and maintain them inproper condition.

l/Vhile we have shown one preferred form of apparatus especially adaptedfor carrying out our improved method, it is to be understood that themethod may be carried on in other forms of apparatus and further thatour method is capable of modification to adapt it to various forms ofapparatus and various materials to be treated. We, therefore,contemplate such changes and modifications as come within the spirit andscope of the appended claims.

We claim:

1. The method of treatment of heavy hydrocarbon material in liquid form,which comprises depositing the material in a closedV chamber upon ahighly heated floor, the rate of.deposit and the heat input to the ioorbeing such as to cause coking on the floor and to maintain a layer ofsubstantially liquid material in the chamber, and periodically stoppingthe deposit of material, continuing the application of heat to theliquid layer until it is coked, and removing the coke from the chamber.v

2. The method of treatmentof heavy hydrocarbon material in liquid form,which comprises depositing the material in a closed chamber upon ahighly heated Hoor, the rate of deposit and the heat input to thefloor'being such that the material is coked progressively from below,building up a layer of coke on the loor and maintaining a layer of thematerial in substantially liquid form upon the coke layer, periodicallystopping the deposit of material, continuing the application of heat tothe liquid layer until it is coked, and removing the coke from thechamber.

Signed by ALEXANDER S. KNowLEs at New York city, New York, this 4th dayof March. 1929, and by CHARLES W. ANDREWS at Chicagd, Illinois, this 28day of lFebruary, 1929.

`ALEXANDER S. KNOWLES.

CHARLES W. ANDREWS.

